Switch contact assembly



N0V-*14 19.67A E. L. GRAYsoN ETAL. 3,352,979

SWITCH CONTACT ASSEMBLY Filed Sept. 30, 1966 FIG. l.

VENTORS EDWA L.. GRAYSON, BY BERNARD J. PERRY WIB L 1 ATT RNEYS.

United States Patent 3,352,979 SWITCH CONTACT ASSEMBLY Edward L.Grayson, West Orange, NJ., and Bernard J. Perry, Manchester, N.H.,assignors to RCL Electronics, Inc., Maplewood, NJ., a corporation of NewJersey Filed Sept. 30, 1966, Ser. No. 583,369 Claims. (Cl. ZOO- 11) Thisinvention relates in general to electrical switch assemblies and moreparticularly, to an electrical switch contact assembly having one ormore bifurcated contact members carried by a rotatable hub for makingelectrically connecting contact between one or more corresponding pairsof spaced electrically conductive surfaces, when said hub is rotatedinto corresponding predetermined angular positions relative to saidsurfaces.

Essentially, the switch contact assembly of the instant inventionprovides a rotatable hub member disposed for rotation about apredetermined axis relative to the conductive surfaces to beelectrically connected, with the rotation axis of said hub member beingdisposed in spatial relation to the pairs of conductive surfaces so thatthe contact members carried by said hub can be brought into thenecessary physical contact with such conductive surfaces for makingelectrical connection therebetween.

The bifurcated contact members are made of a resilient, electricallyconductive material, such as metal, and are generally W-shaped.Preferably, these contact members are formed from thin sheet or stripstock oriented to provide a lon-g dimension along the plane of rotationof the hub, vand a thin dimension transverse thereto.

The hub member is preferably lconstructed in the form of a disc, and ofan electrically insulating material where it is desired to electricallyisolate said hub member from the various electrical circuits made by itscontact members. The hub disc is provided with a number of dowel membersequal to the number of contact members carried, said dowel members beingoperatively connected to the hub member, each dowel being disposed inoperative engagement wtih a contact member for releasably fastening sameto said hub to be carried thereby.

The contact members are disposed on the hub in a predetermined angularand radial relation to each other and with respect to correspondingpairs of conductive surfaces so that each of such conductive surfacepairs can be brought into Contact with the extended outer legs of aselected contact member for electrical connection therebetween when thehub is rotated into corresponding angular positions relative to saidconductive surfaces.

One advantageous feature of the instant invention lies in the fact thatindividual contact members can be easily removed from and replaced uponthe hub to adapt the switch assembly for various switching contactarrangements, For this purpose, the dowels are extended transversely tothe disc hub, land are secured thereto by any conventional means, suchas a press t,-etc., so that -portions at the opposite end of each dowelprotrude beyond the axially disposed sides of the hub. The contactmembers are each provided witha pair of oppositely disposed perforationswhich are disposed on opposite reentrant leg portions of the W-shapedContact member for operative engagement with the dowel protrusions. Thisarrangement enables the contact members to be releasably fastened to thehub simply by spreading apart their reentrant leg portions and slidablyinserting their perforations over said dowel protrusions to secure thecontact members to the hub. In the installed condition, the dowelprotrusions extend through the reentrant leg perforation-s and constrainthe contact members against radial movement relative to the hub. Byreason of the W-shape of the Acontact members, each contact member has acentrally disposed closed loop portion which, when'the contact memberis`installed over the dowel protrusions, is held against the -peripheraledge of the hub. When thus installed, the contact members can be removedby reversing the aforementioned procedure. Under normal operatingconditions, the contact members are constrained against movementrelative to the hub along its axial direction by their reentrant legportions which are connected by the closed loop portion and straddle theopposite sides of the hub disc.

Although it is not absolutely necessary, the switch contact assembly ofthe instant invention provides means for constraining the contactmembers from rotating relative to the hub about their respective dowelaxes.

As can be appreciated by the artisan, numerous means Iare potentiallypossible for constraining such rotation, the invention provides suchmeans in the form of radially disposed notches recessed into theperiphery of the hub, and disposed for operative engagement with theclosed loop portions of the `Contact members. In such case, the dowelsare positioned radially in relation to the radial distance between thecontact member perforations and the inside surface of said closed loopportions so that, when said Contact members are installed on the hub,their. closed loop portions engage into the notches and are held firmlyagainst the inner boundary surfaces thereof.

With the switch contact assembly of the invention, one or more contactmembers can be carried by a hingle hub, the exact number depending uponthe size of the contact members, which are preferably of uniformconstruction, in relation to the available circumferential space on thehub disc. In typical applications of the switch contact construction,according to the invention, as many as six contact members can beinstalled on a hub of modest diameter, such as would be suitable forelectronic equipment packaged in accordance vwith conventional standardsof compactness.

It is therefore an object of the invention to provide a rotatable switchContact assembly for electrically connecting one -or more pairs ofspaced apart electrically conductive surfaces.

Another object of the invention is to provide a switch contact assemblyas aforesaid, having switching contact members that can be simplyinstalled and removed to adapt the assembly for a variety of switchingconfigurations.

A further object of the invention is to provide a switch contactassembly as aforesaid which is capable of multipole switching operation.

Still another and further object of the invention is to provide a switchcontact assembly as aforesaid which features interchangeably replaceablecontact members for greater useful operating life, and to accommodatevarious switching current capacity requirements.

Other and further objects and -advantages of the invention will becomeapparent from the following detailed description and accompanyingdrawings in which:

FIG. l is a schematic longitudinal View, partly in section, of arotatable switch contact assembly, according to a preferred embodimentof the invention, as installed in relation to a typical arrangement ofthe conductive surfaces to be electrically connected thereby.

FIG. 2 is an axial view of the -switch contact assembly of FIG. l,showing the installation of a typical contact member thereon.

- 1y conductive surfaces 13a, 13a and 14a, 14a.

Thehub 11 is preferably constructed in the form of a disc, and from anelectrically insulating material, such as plastic, etc., and is disposedfor rotation about a longitudinal axis X-X relative to the conductivesurfaces 13a, 13a', 14a, being also disposed in spatial relation to thepairs of conductive surfaces 13a, 13a' and 14a, 14a', so that thecontact members 12 and 12' carried by said hub 11 can be brought intothe necessary physical contact with the surface pairs 13a, 13a and 14a,14a', respectively, as illustrated in FIG. 1, by rotating said hub 11into a corresponding angular position, and thereby effecting electricalconnection of the surfaces 13a and 13a via the con- -tact member 12, andlikewise electrically connecting the sur-faces 14a and 14a' via thecontact member 12.

The contact members 12 and 12 are bifurcated, and are generally Wshapedin form. These contact members 12 and 12 are made of an electricallyconductive, resilient material, such as a spring-type of metal, and arepreferably formed from thin sheet or strip stock oriented to provide along dimension along the plane of rotation of the hub 11 and a thindimension transverse thereto.

The hub disc 11 is provided with a plurality of dowel members 15 equalin number to that of the contact members 12, 12', etc., to be carried onsaid hub 11. The dowels 15 are disposed in a spaced-apart angular andradial arrangement on the hub 11, corresponding to that of the contactmembers 12 and 12', and are operatively connected to said hub 11 by anysuitable conventional means, such as for example, by press-fitting theminto transverse holes 16 extending through said hub 11. The dowels 15serve for releasably fastening the contact members 12 and 12 to the hub11, with each contact member 12 and 12v being disposed in operativeengagement with a dowel 15.

Each dowel 15 is secured to the hub 11 as aforesaid, so that oppositeend portions 17 of each dowel 15 protrude beyond the axially disposedsides 18 of the hub 11. The contact members 12 and 12 are provided withpairs o-f oppositely disposed perforations 19, which are disposed onopposite reentrant leg portions 20y of the W-shaped contact members 12and 12 for operative engagement with the dowel protrusions 17. Thisarrangement permits the contact members 12 and 12 to be releasablyfastened to the hub 11 by-simply spreading apart their reentrant legportions 20 and slidably inserting their perforations 19 over said dowelprotrusions 17.

In this inst-alled condition, as represented by FIG. l, the dowelprotrusions 17 extend through the perforations 19 and thereby constrainthe contact members 12 and 12' against radial movement relative to thehub 11.

As can be noted from the W-shaped contact members 12 and 12', each has acentrally disposed closed loop portion 21, which in the installedconfiguration, is held against the peripheral edge of the hub 11, orpreferably against the inner surface 22 of a notch 23 to constrain ysaidcontact members 12 and 12 from rotating relative 'to said hub 11 laboutthe longitudinal axes of the ldowels 15.

When thus installed, the individual contact members v12 and 12 can beremoved and/ or replaced by following the aforesaid procedure, reversingits steps for removal of said contact members 12 and 12.

As can be appreciated by the artisan, the simple contact member 12 and12 installation and removal procedures afforded by the invention, can beutilized to adapt the switch contact assembly 10 for various switchingconfigurations.

' While only two installed contact members 12 and 12 are illustrated forsimplicity in FIG. 1, and the hub 11 as shown in FIG. 2 is provided withthe capability for attaching four contact members (only one shown), itis understood that the number of contact members 12, 12',

ctc., mounted to the hub in any given application can be varied, asdesired, and the number of such contact mem- 14a, said rotation axis X-Xand the hub 11A bers 12., 12', etc., that can be carried by a is limitedonly by the space available thereon.

The contact members 12 and 12 are disposed on the hub 11 in -a xedangular and radial relation to one another, and with respect tocorresponding pairs of conductive surfaces 13a, 13a and 14a, 14arespectively, so that whenthe hu'b 11 is rotated into correspondingangular positions, the extended outer legs 24 of said cprltact members12 and 12 are in physical, electrically conducting contact with bothsurfaces 13a, 13a and 14a,114a' in each respective surface pair.

In any given application of the invention, the angular and/ or radialarrangement of the contact members 12, 12', etc., upon the hub 11 can bevaried to correspond with the arrangement of the conductive surfaces tobe electrically connected to one another.

As illustrated in FIG. l, the installed contact members 12 and 12 areconstrained againstraxial movement -relative to the hub 11 along itsaxial direction by their reentrant leg portions 20 which are preferablyformed parallel to the sides 1S of said hub 11, said leg portions 20being connected by the closed loop portion 21, so as to straddle bothsides 18 of said hub 11.

While it is not absolutely necessary to provide the recessed notches 23to constrain the contact members 12 and 12 from rotating about theirdowel 15 fastening, since the peripheral edge of the disc-lil e hub 11inherently limits such rotation, the notches 23 can be advantageouslyprovided to substantially eliminate any such rotation. The notches 23are preferably radially disposed for operative engagement with theclosed loop portions 21 of the contact members 12 Iand 12', and,accordingly, are recessed to a depth which, taking into account theradial positions of the d-owels 15 and the effective-radial distancebetween the perforations 19 and the inside surface of said closed loopportions 21, permits the contact members 12 and 12' to be installed onthe hub 11 with their closed loop portions 21 held securely `against theinner boundary surfaces 24 of said notches 23.

For practical reasons, the contact members 12 and 12' are preferablyconstructed uniformly, and/or for interchangeable installation upon thehub 11. Likewise, and even more so, the dowels 15 and notches 23, andtheir arrangement on the hub 11 is preferably uniform.

As will be apparent to those skilled in the art, the single dowel 15provide-d for fastening individual Contact members 12 and 12 can bereplaced by a plurality of dowels or by a pair of stud pins (notshown)fastened to the hub 11 and protruding from each side 18 thereof,to accomplish the same result effected by the single dowels 15 pressedthrough said hub 11. Y

What is claimed is:

1. A rotatable switch contact assembly which comprises a pair of spaced,electrically conductive surfaces,

a rotatable hub member disposed for rotation relative to said conductivesurfaces about an axis generally perpendicular to said conductivesurfaces, a dowe'l member operatively connected to said hub member andcarried thereby, a W-shaped, bifurcated, electrically conductive contactmember for electrically connecting said conductive surfaces, saidcontact member being disposed in` operative engagement with said hubmember and with said dowel member for fastening said contact member tosaid hub member to be carried thereby, said contact member beingdisposed on said hub member in relation t-o said spaced conductivesurfaces to contract both of said conductive surfaces and therebyelectrically connect same when said h-ub member is rotated into .apredetermined angular position.

2. The switch contact assembly according to claim l, wherein said -hubmember is made of an electrically insulating material.

3. The switch contact assembly according to claim 1, wherein saidcontact member is formed from flat stock, resilient, conductive materialoriented to provide a long dimension along the plane of rotation of saidhub member and a thin dimension transverse thereto.

4. The switch contact assembly according to claim 3, wherein said hubmember is in the form of a disc, and wherein said dowel member extendstransversely through said disc hub member and protrudes beyond each sidethereof, and including means defining an oppositely disposed pair ofperforations in said contact member, each of said perforations beingdisposed on an opposite reentrant leg portion of said W-shaped contactmember for operative engagement with said dowel member to releasablyfasten said contact member to said hufb member, whereby said contactmem-ber can be releasably fastened to said hub member by spreading apartsaid reentrant leg portions and slidably inserting said perforationsthereon over said dowel member protrusions to secure said contact memberto said hub member with said dowel protr-usions extending through saidreentrant leg perforations and with a closed loop portion of saidc-ontact member being held against the peripheral boundary of said dischub member.

5. The switch contact assembly 'according to claim 4, including meansdening a radially disposed notch recessed into the periphery of said hubmember, said notch being disposed for -operative engagement with theclosed loop portion of said contact member to constrain said contactmem-ber from rotation relative to said hub member about said dowelmember.

6. A rotatable switch contact assembly which comprises a plurality ofpairs of spaced, electrically conductive surfaces, a rotatable hubmember disposed for rot-ation relative to said conductive surfaces aboutan axis generally perpendicular to said conductive surfaces, a pluralityof dowel members operatively connected to said hub member and carriedthereby, a corresponding plurality of W-shaped, bifurcated, electricallyconductive contact members for electrically connecting said pairs ofconductive surfaces, said contact members being disposed in operativeengagement with said hub member and with corresponding dowel members forfastening said contact members to said hub member to be carried thereby,said contact members being disposed on said -hub member in predeterminedrelation to corresponding pairs of said conductive surfaces to contactboth conductive surfaces in each corresponding pair thereof, and therebyelectrically connect same when said hub member is rotated intocorresponding angular positions.

7. The switch contact assembly according to claim 6,

thereof, said dowel members wherein said hub member is sulatingmaterial.

8. The switch contact assembly according to claim 6, wherein each ofsaid cont-act members are substantially similar, and are formed fromflat stock, resilient, conductive material oriented to provide a longdimension along the plane of rotation of said bub member and a thindimension transverse thereto.

9. The switch contact assembly according t-o claim 8, wherein said hubmember is in the for-m of a disc, and wherein said dowel members extendtransversely through said disc hub member and protrude beyond each sidebeing disposed at predetermined spaced-apart angular positions on saidhub member, and including means defining an oppositely disposed pair ofperforations in each of said contact members, each of said perforationsbeing disposed on opposite reentrant leg portions of said W-shapedcontact members for operative engagement with corresponding dowelmembers to releasably fasten said contact members to Said hub member atpositions thereon corresponding to the positions of their respectivedowel members, whereby said contact members can be releasably fastenedto said hub member by spreading apart their reentrant leg portions andslidably inserting said perforations thereof ove-r corresponding dowelmember protrusions to secure said contact members to said hub memberwith said dowel protrusions extending through said reentrant legperforations and with a closed loop portion of each contact member beingheld against the peripheral boundary edge of said disc hub member.

10. The switch contact assembly according to claim 9, including meansdefining a plurality of radially disposed notches recessed into theperiphery of said hub member, said notches being disposed for operativeengagement with the closed loop portions of corresponding contactmembers to constrain said contact members from rotation relative to saidhub member about their respective dowel members.

made of an electrically in- References Cited UNITED STATES PATENTS3,213,212 10/1965 Sefton 3,258,547 6/1966 Rector

1. A ROTATABLE SWITCH CONTACT ASSEMBLY WHICH COMPRISES A PAIR OF SPACED,ELECTRICALLY CONDUCTIVE SURFACES, A ROTATABLE HUB MEMBER DISPOSED FORROTATION RELATIVE TO SAID CONDUCTIVE SURFACES ABOUT AN AXIS GENERALLYPERPENDICULAR TO SAID CONDUCTIVE SURFACES, A DOWEL MEMBER OPERATIVELYCONNECTED TO SAID HUB MEMBER AND CARRIED THEREBY, A W-SHAPED,BIFURACTED, ELECTRICALLY CONDUCTIVE CONTACT MEMBER FOR ELECTRICALLYCONNECTING SAID CONDUCTIVE SURFACES, SAID CONTACT MEMBER BEING DISPOSEDIN OPERATIVE ENGAGEMENT WITH SAID HUB MEMBER AND WITH SAID DOWEL MEMBERFOR FASTENING SAID CONTACT MEMBER TO SAID HUB MEMBER TO BE CARRIEDTHEREBY, SAID CONTACT MEMBER BEING DISPOSED ON SAID HUB MEMBER INRELATION TO SAID SPACED CONDUCTIVE SURFACES TO CONTACT BOTH OF SAIDCONDUCTIVE SURFACES AND THEREBY ELECTRICALLY CONNECT SAME WHEN SAID HUBMEMBER IS ROTATED INTO A PREDETERMINED ANGULAR POSITION.